1. Field of the Invention
This invention relates to electronic counting and recording devices, and more particularly to an electronic apparatus for counting and recording a number of drops of fluid.
2. Description of Related Art
In a number of fields, it would be useful to count the number of drops of fluid released from a reservoir or source, or passing through a conduit. In some cases, it would also be useful to be able to determine and record the time period during which such drops are released. For example, in the medical field, ophthalmologists and other health professionals have long suspected that patients do not use their eyedrop medications as directed. It is therefore desirable to monitor the compliance of patients with directions for usage of eyedrops.
A number of attempts have been made to monitor patient compliance in ophthalmology. One such system used a base unit having a receptacle for a medication bottle. The (presumed) use of the medication is recorded by an electronic memory system, provided that the patient replaces the medication bottle into the base unit each time it is used. See R. Yee et aI., Medication Monitor for Ophthalmology, Amer. J. Optical. 78:774-778 (1974). Disadvantages of this system are that the medication bottle can be easily separated from the base unit, the system is too bulky to fit conveniently in a pocket, and the appearance differs from commercially available bottles.
Further, this system does not monitor the amount of medication actually released from an eyedrop bottle, but only the approximate times that the bottle is removed from its receptacle.
A second system used a holding unit with a receptacle for a medication bottle. The (presumed) use of the medication is recorded by an electronic memory system when the bottle cap is removed. See S. Norell et aI., A Medication Monitor and Fluorescein Technique Designed to Study Medication Behaviour, Acta Ophthalmologica, 58:459-467 (1980). Disadvantages of this system are that the system is too bulky to fit conveniently in a pocket and the appearance differs from commercially available bottles. Further, this system does not monitor the amount of medication actually released from an eyedrop bottle, but only the approximate times that the bottle cap is removed from the bottle.
A third system used a special bottle into which the contents of a medication bottle are transferred. The (presumed) use of the medication is recorded by an electronic memory system when the bottle cap is removed and the bottle is inverted. See Kass et aI., A Miniature Compliance Monitor for Eyedrop Medication, Arch Ophthalmol., 102:1550-1154 (1984). Disadvantages of this system are that the system requires transfer of medication from commercially available bottles, which may lead to contamination, and the system does not monitor the amount of medication actually released from an eyedrop bottle, but only the approximate times that the bottle cap is removed and the bottle inverted.
Ideally, an eyedrop compliance monitoring system would detect and record the actual number of eye drops used by a patient, and the time period during which the drops were used. This more accurate recorded information could then be read out by a doctor and used to evaluate the efficacy of a particular treatment.
Another advantage of being able to record both the number of drops released from a source and the time periods during which such drops are released is to provide a reminder signal or indication to a patient as to the dosage and appropriate time for each eyedrop administration.
Yet another advantage of being able to record both the number of drops released from a source and the time periods during which such drops are released is to monitor over and under medication by a patient. An alarm may be used in such a case to alert the patient of the condition.
It would be desireable to provide an eyedrop compliance monitoring system that may be adapted to these uses and which accommodates existing medication bottles, is inexpensive to manufacture, and is convenient to carry in a pocket or purse.
Accordingly, it is highly desirable to provide a compact, inexpensive, and accurate fluid drop counting and recording apparatus that optionally can "time stamp" the occurrence of drop releases and/or provide an indication as to the dosage and appropriate time for each eyedrop administration.